hive

hive 写入分区

insert overwrite table dws_jd_erp_purchase_transfer partition(dt)
select * from
data_kezhi.dws_jd_erp_purchase_transfer
where dt = '${bizdate}'

hive导数据到csv

insert overwrite local directory '/home/hadoop/lijicong/test' row format delimited fields terminated by ',' select * from dw.ol_api_consume_channel_fact where month_num = 201902;

hive新增字段

alter table dw.ods_aabb_v9_design add columns(status int);


alter table detail_flow_test add columns(original_union_id string);


alter table dw. ods_aabb_v9_mp_account add columns(is_quality int);


alter table dw.ods_traf_already_recommended add columns(version string);


alter table dw.ods_aabb_v9_picture_page add columns(recommend int);

hive优化

• 1、小表放前面，使用map join
• 2、避免数据倾斜
• 3、合理设置map、reduce数
• 4、优化sql写法减少job数
• 5、尽量不对字段进行函数计算